标题： 行星状星云 显示英文标题

标题： Planetary Nebulae

摘要： 行星状星云是由质量约为太阳0.8到8倍的低至中等质量恒星在其生命末期喷发的物质形成的。 当氢燃料耗尽后，恒星会膨胀，随后氦燃料也会耗尽。 在这些巨星阶段，恒星还会失去大量的质量。 在核心氦燃料耗尽后的第二次巨星阶段，质量损失如此之大，以至于恒星会失去其大部分质量（50%到90%），留下一个小型且炽热的核心，称为白矮星，周围环绕着星云。 行星状星云是许多过程的结果，这些过程塑造并改变了它们的电离结构和化学成分。 由残余极热恒星核心发出的富含紫外光谱照亮的星云，是美丽与科学的奇观。 在本章中，我们展示了这些天体对于天体物理学、天体化学和天体矿物学研究来说是不可或缺的实验室，并对天文学的多个领域产生了影响。 显示英文摘要

摘要： Planetary nebulae are formed by the matter ejected by low-to-intermediate mass stars (~0.8-8 times the mass of the Sun) towards the end of their lives. As hydrogen and then helium fuel sources run out, stars expand. During these giant phases stars also lose sizable amounts of mass. During the second giant phase, after the exhaustion of core helium, the mass loss is so great that stars lose a large fraction of their mass (50 - 90%), leaving behind a small, hot core, known as a white dwarf, surrounded by a nebula. Planetary nebulae are the result of many processes that shape and alter their ionization structure and chemical composition. The resulting nebula, illuminated by the ultraviolet-rich spectrum of the remnant very hot stellar core, is a spectacle of beauty and science. In this chapter, we show that these objects are invaluable laboratories for astrophysics, astrochemistry, and astromineralogy studies, with impact in many areas of Astronomy.